Disc-type brake for thread

ABSTRACT

A disc-type brake for thread, with two discs mounted with freedom to rotate, these discs being pressed together by an energy store fitted on a mounting. The energy store acts on the discs eccentrically in relation to their spindle. An inclined bearing surface is provided between the discs so that the planes of rotation of the discs are at an angle to each other.

United States Patent Rosen 1451 Jan. 9, 1973 s41 DISC-TYPE BRAKE FOR THREAD 2,190,261 2/1940 Feast/er ..242/14'/ M 2,593,045 4/1952 Maroshick t ..l88/7l.l X [761 [m Rmnv 2,6l4,773 10/1952 Ammerall ..242/147 M Ulrwehamn, Sweden 2,881,988 4/1959 Warwick ..242/150 22 F] d: .4 1971 I l l e Primary Examiner-Even C. Blunk [21] Appl. N0.: 103,706 Assistant Examiner-Merle F. Maffei Attorney-Woodhams, Blanchard & Flynn [30] Foreign Application Priority Data [57] ABSTRACT Jan- 5, Gennany.....................P 00 A brake for thread two discs mounted with freedom to rotate, these discs being pressed [52] US. Cl ..l88/7l.l, 29/5l3, 242/147 M mgchel. by an energy More fined on a mounting The [51] Ill. Cl ..Fl6d 55/00 energy store acts on the discs eccentricauy in reunion [58] Field searchmlss/n'lv 242/l47 to their spindle. An inclined bearing surface is pro- 242/l50i 29/5 I 3 vided between the discs so that the planes of rotation of the discs are at an angle to each other. [56] References Cited 9 Claims, 5 Drawing Figures UNlTED STATES PATENTS 1,824,669 9/1931 Jordhoy ..l88/l64 w E 1 i':: T i r 1 PATENTED JMI 9 I973 3, 709 .332

INV ENTOR KARL ISAC JOEL ROSE/V zf wi m jzm DISC-TYPE BRAKE FOR THREAD The invention relates to a disc-type brake for thread, with two discs mounted with freedom to rotate, the discs being pressed together by an energy store fitted to part of the mounting.

In some known disc brakes, a spring serving as the energy store holds both discs together against a stop. Though both the discs are mounted loosely on a spindle, the frictional forces between the one disc and the spring and between the other disc and the stop are so great that a thread running through between the discs is unable to turn them. The disadvantage of this is that with a multi-strand yarn individual strands get caught up, accumulate between the discs and foul the brake. Since the very purpose of the brake is to apply as constant a tension as possible to the thread passing through, this is a serious drawback. Moreover, a disc brake such as described produces difficulties in the insertion of the thread, which, when tension is low, will not readily enter between the discs.

To overcome these difiiculties, attempts have been made to induce the discs to rotate along with the thread as this passes through, by mounting the discs on a spindle made of low-friction material such as glass or a ceramic material, for example, and giving the spindle a certain thickness. The result of this is that the frictional force arising between the thread and discs is applied eccentrically, the torque acting on the discs being increased. However, this torque has been found inadequate in relation to the frictional forces involved.

In other existing disc-type brakes, magnets are provided by way of energy stores. In one such brake, permanent bar magnets are arranged in a ring about a stationary spindle parallel to them. The spindle carries a loose bush, on which the two discs are mounted, loosely again. As the magnets are arranged regularly in a closed circle and hence the upper disc is pulled uniformly against the lower one, there is a possibility, with this brake also, of a too lightly tensioned thread not being drawn in between the discs. The same applies to two other existing disc brakes fitted with magnetic energy stores, in both of which the magnet is in the form of a closed ring. In the case of these two types of brakes, moreover, the disc that is not magnetizable and lies nearer to the magnet is mounted rigidly on a stationary spindle. All these disc brakes are somewhat complicated in design.

The purpose of the invention is to provide a disc brake of the type referred to in the preamble, which, while being of simple and robust construction, is trouble-free in operation and readily takes even a weakly tensioned thread between its discs.

This purpose is achieved by the invention by virtue of the fact that the energy store acts on the discs eccentrically in relation to their axis of rotation and that an inclined bearing surface is provided between the discs, the planes of rotation of the two discs being at an angle to each other.

With the brake so designed, a one-sided gap is produced between the discs, into which even a weakly tensioned thread is bound to slip. The eccentric arrangement of the energy store, in conjunction with the inclined bearing surface, ensures that there will be a sufficient area of contact between the discs for the desired tensioning of the thread, while the size of that area can be precisely determined by the formation of the bearing surface. Eccentric positioning of the energy store enables the brake to be of simple construction, since the axis of rotation of the discs and the energy store do not conflict with each other. It is true that one of the discs in one of the brakes described above can be set obliquely to the other in certain circumstances. This oblique setting, however, is not permanent, nor is it at any particular angle, but is brought about by the thread itself as the tension on the thread rises. To that end, the thread is carried round a change-of-direction roller or the like at a distance from the brake, while the disc intended to be set obliquely is joined to a tilting bearing. This bearing is positioned off center in relation to the disc, at a point remote from where the thread is diverted. in addition, the tilting bearing lies at that point on the disc periphery which is remote from the energy store. ln this brake, both discs are non-rotary. The oblique setting necessitates not only a change of direction for the thread, but also a separate bearing. Not only is such a brake very expensive to make, but its action is precisely the opposite of that of the brake now proposed. The effect sought in the latter is that the discs may readily be turned along with the thread as it is drawn through, while the oblique setting of the discs, which is permanent in the brake here proposed, is intended to permit the introduction of a weakly tensioned thread. in the brake already known, there is no oblique setting at all until it is brought about by a particularly heavily tensioned thread.

The bearing surface should be conical and should lie concentric with the axis of rotation. This is a simple means of ensuring the obliquity of the two discs even when both of them are turning in relation to a stationary energy store. There is no reason, moreover, why the latter should not be spaced away from the discs, and it may therefore take the form of a conventional adjustable magnet. Then, as the one disc rotates, it carries out a tumbling movement, yet it always lies on the other disc with a pressure determined by the power of the energy store and the contact area is governed by the shape of the bearing surface. The braking action so achieved can thus be precisely pre-determined.

As already mentioned, the energy store may well be a magnet, preferably a permanent magnet, with a conventional means of axial adjustment for regulating the contact pressure between the discs. Contrary to the existing types of brakes previously referred to, which produce concentric contact pressure by means of complicated arrangements such as ring magnets, or bar magnets arranged ring-fashion, the brake made in accordance with the invention requires only one single magnet, fitted eccentrically in relation to the axis of rotation, which simplifies construction.

A particularly simple design for a disc-type brake, which is especially favorable for the brake described above in accordance with the invention, but also has advantages for brakes with central energy stores, and for which separate protection is therefore sought, provides for the discs and their spindle to be combined into a single unit that can be inserted into the mounting portion. The advantages of this feature lie both in simplicity of production and in the ready interchangeability of such units in cases where changes are made in the method of working and/or the nature of the thread used in the processing installation to which the mounting portion is secured. Another advantage is that the spindle that can be loosely inserted into the mounting portion ensures particularly easy running of both discs. The energy store may then well be permanently incorporated in the mounting portion, but another possibility is for it to be fixed to the said unit.

In one recommended version, of particularly simple design, one disc is rigidly mounted on the spindle.

Another advantageous feature of the disc brake here proposed is that at least one of the discs may contain openings through which scourings can readily pass to the outside. The brake thus becomes self-cleaning, so that any falling-off in braking action is avoided.

Practical examples of the invention are shown in the accompanying drawings, in which:

FIG. 1 shows a somewhat diagrammatic representation of a disc-type brake such as now proposed;

FIG. 2 shows the same brake as FIG. I, as seen from below;

FIG. 3 is a plan of the brake shown in FIG. 1;

FIG. 4 is an exploded view showing the components of the brake shown in FIG. 1; and

FIG. 5 is another example of a brake embodying the principle of the invention.

The brake shown in FIG. I has a mounting portion, 1, which can be attached by some means (not shown) to a thread processing installation. This mounting is circular in cross-section, as can be seen from FIGS. 2 and 3. A fixed spindle, 2 (FIG. 4) is fitted centrally in the mounting, from which it projects. Also fixed within the mounting, parallel to but at a distance from the spindle, is a magnet, 3, the action of which is exerted axially.

Two discs, 4 and 5, are mounted axially on the mounting l with freedom to rotate. The disc 4, which is nearer to the mounting, is made of non-magnetizable material in the present case, plastics. The disc 5, which is remote from the mounting, is made of magnetizable material.

One face of the plastics disc 4 carries a hub, 6, containing a bore, 7, by which the disc can be fitted on to the fixed spindle 2. On its opposite face, that is to say the face which lies towards the disc 5 in the working position, the disc 4 incorporates a concentric conical bearing surface, 8, for the disc 5. This bearing surface 8 is made in one both with the disc 4 and with a bearing bushing, 9, of relatively large diameter, which terminates in a shallow flange, 10. The bearing bushing 9 serves as anchorage for the disc 5, which is prevented from falling off by the flange 10. The disc 5 can be passed over the bushing 9 because the central opening in the disc, the diameter of which is the same, except for a slight degree of play, as that of the bushing 9, is extended by other openings, 11, which leave between them tabs, 12, which are slightly bent upwards and can be sprung a trifle to enable them to'be pushed over the flange I0.

As can be seen from FIG. 1, the off-center action of the magnet 3, which exerts a one-sided pull on the magnetizable disc 5 towards the bearing surface 8 on the disc 4, results in the disc 5 adopting an oblique setting in relation to the disc 4, so that a gap is produced between the two discs at the side directly opposite the point of application of the magnet. The thread F, drawn in chain-line in FIGS. 1 and 3, enters this gap and thus finds its way between the discs 4 and 5. Since, owing to the relatively large diameter of the bushing 9, it exerts a frictional force acting eccentrically on the two discs (FIG. 3), it causes them to rotate with it in the direction shown by the arrow A, the disc 5 executing a tumbling movement on the disc 4. The amount of contact pressure between the two discs can be regulated either by making the spindle 2 adjustable for height (not shown in the drawing) or providing for axial displacement of the magnet 3 (likewise not shown).

Another form of disc brake is shown in FIG. 5. A positioning member, 13, which carries an external thread, can be varied in height by rotation in a threaded bore, 14, in the mounting 1'. This rotation is brought about with the aid of the circular plate I5, made in one piece with the plastics positioning member 13. A spindle, 16, for the discs, can be inserted in the positioning member 13. This spindle I6 is rigidly fixed to the plastics disc 4', which is made in one piece with a bearing bushing, 9, for the magnetic disc 5, as described in connection with FIG. 1. The two discs 4' and 5 form with the spindle 16 a unit, which it is easy to insert into or remove from the mounting.

By way of energy store, the brake shown in FIG. 5 has a substantially ring-shaped permanent magnet, 3'.

The invention is not limited to the practical examples illustrated. In particular, in the case of a brake such as shown in FIGS. l to 4, the two discs may form a unit with a spindle, as in the example appearing in FIG. 5, in which event the mounting will be provided with a suitable bushing to take the spindle. The brake shown in FIG. 5 can likewise have a magnet placed off center and the disc 4' may have a conical bearing surface.

Moreover, it is immaterial to the scope of the invention whether the magnets used be permanent magnets or electro-magnets. Furthermore, a spring may be used for the off-center energy store. According to circumstances, this spring may be combined with the two discs and the spindle to form a single unit and be fitted with it to the mounting.

Again, the bearing surface may be rigidly attached to the magnetizable disc or made in one with it. A further possibility, in the case of an arrangement in which the energy store and one disc do not alter their relative positions whether the energy store rotates as well or both components are stationary is for the bearing surface to be eccentric in shape.

What we claim is:

I. A disc-type brake for a thread, the combination comprising support means, a pair of rotatable discs mounted on said support means, said pair of discs being positioned adjacent one another and having opposed bearing surfaces, and actuating means for causing the bearing surfaces of said discs to be pressed against one another, the improvement wherein said actuating means acts on said discs eccentrically relative to their rotational axes for causing said opposed bearing surfaces to be pressed against one another, the bearing surface of one of said discs being nonplanar and inclined relative to the bearing surface of the other disc for causing the rotary planes of said discs to form a con tinuous angle between them as the discs rotate, said discs contacting one another only at a location adjacent the actuating means to form the vertex of said angle when so contacted.

2. A disc-type brake according to claim 1, wherein the bearing surface of said one disc is of a conical configuration which is substantially concentric with the rotational axis of said one disc, the conical configuration of the bearing surface on said one disc converging in a direction toward the bearing surface of said other disc.

3. A disc-type brake according to claim 2, wherein the bearing surface on said other disc is substantially planar.

4. A disc-type brake according to claim 1, wherein the nonparallel and inclined bearing surface is made of one piece with said one disc.

5. A disc-type brake according to claim 1, wherein the actuating means comprises a magnet, one of said discs comprising a magnetizable material and the other of said discs comprising a nonmagnetizable material.

6. A disc-type brake according to claim 5, wherein the actuating means comprises a permanent magnet.

7. A disc-type brake according to claim 5, further including means mounting said magnet for adjustable movement thereof toward and away from the discs for varying the force of the magnet on the discs causing the bearing surfaces to be pressed against one another.

8. A disc-type brake according to claim 1, wherein one of said discs has a central opening therein, and the other of said discs having a central hub fixedly secured thereto and extending axially outwardly beyond the bearing surface thereof, said hub extending through the central opening of said one disc for movably supporting said other disc.

9. A disc-type brake according to claim 8, wherein the free end of said hub has a radially outwardly extending flange thereon, and wherein said one disc has a plurality of resilient tabs positioned in surrounding relationship to the central opening for enabling said flange to be passed through said opening due to resilient deflection of said tabs, whereby said tabs then return to their normal position wherein they project radially inwardly beyond said flange for retaining said one disc on said hub.

# l i 1F 

1. A disc-type brake for a thread, the combination comprising support means, a pair of rotatable discs mounted on said support means, said pair of discs being positioned adjacent one another and having opposed bearing surfaces, and actuating means for causing the bearing surfaces of said discs to be pressed against one another, the improvement wherein said actuating means acts on said discs eccentrically relative to their rotational axes for causing said opposed bearing surfaces to be pressed against one another, the bearing surface of one of said discs being nonplanar and inclined relative to the bearing surface of the other disc for causing the rotary planes of said discs to form a continuous angle between them as the discs rotate, said discs contacting one another only at a location adjacent the actuating means to form the vertex of said angle when so contacted.
 2. A disc-type brake according to claim 1, wherein the bearing surface of said one disc is of a conical configuration which is substantially concentric with the rotational axis of said one disc, the conical configuration of the bearing surface on said one disc converging in a direction toward the bearing surface of said other disc.
 3. A disc-type brake according to claim 2, wherein the bearing surface on said other disc is substantially planar.
 4. A disc-type brake according to claim 1, wherein the nonparallel and inclined bearing surface is made of one piece with said one disc.
 5. A disc-type brake according to claim 1, wherein the actuating means comprises a magnet, one of said discs comprising a magnetizable material and the other of said discs comprising a nonmagnetizable material.
 6. A disc-type brake according to claim 5, wherein the actuating means comprises a permanent magnet.
 7. A disc-type brake according to claim 5, further including means mounting said magnet for adjustable movement thereof toward and away from the discs for varying the force of the magnet on the discs causing the bearing surfaces to be pressed against one another.
 8. A disc-type brake according to claim 1, wherein one of said discs has a central opening therein, and the other of said discs having a central hub fixedly secured thereto and extending axially outwardly beyond the Bearing surface thereof, said hub extending through the central opening of said one disc for movably supporting said other disc.
 9. A disc-type brake according to claim 8, wherein the free end of said hub has a radially outwardly extending flange thereon, and wherein said one disc has a plurality of resilient tabs positioned in surrounding relationship to the central opening for enabling said flange to be passed through said opening due to resilient deflection of said tabs, whereby said tabs then return to their normal position wherein they project radially inwardly beyond said flange for retaining said one disc on said hub. 